Replace live_routes database table with in-memory routing table

- Remove live_routes table from SQL schema and all related indexes
- Create new internal/routingtable package with thread-safe RoutingTable
- Implement RouteKey-based indexing with secondary indexes for efficient lookups
- Add RoutingTableHandler to manage in-memory routes separately from database
- Update DatabaseHandler to only handle persistent database operations
- Wire up RoutingTable through fx dependency injection
- Update server to get live route count from routing table instead of database
- Remove LiveRoutes field from database.Stats struct
- Update tests to work with new architecture

Makefile

@@ -15,7 +15,7 @@ lint:
 	golangci-lint run
 
 build:
-	go build -o bin/routewatch cmd/routewatch/main.go
+	CGO_ENABLED=1 go build -o bin/routewatch cmd/routewatch/main.go
 
 clean:
 	rm -rf bin/